Table 2.
Phenolic compounds of citrus seeds (mg/100 g)
| Control | 60 °C | 70 °C | 80 °C | |
|---|---|---|---|---|
| Kinnow mandarin | ||||
| Gallic acid | 5.113 ± 1.323*c | 6.185 ± 0.367b | 9.720 ± 0.797a | 4.496 ± 0.369d |
| 3.4-Dihydroxybenzoic acid | 4.412 ± 0.555b** | 12.113 ± 0.472a | 2.280 ± 0.718d | 3.641 ± 0.461c |
| (+)-Catechin | 9.341 ± 0.038a | 3.371 ± 0.142d | 6.105 ± 0.203b | 5.962 ± 0.270c |
| 1.2-Dihydroxybenzene | 13.171 ± 2.851a | 5.699 ± 0.258c | 2.517 ± 0.861d | 6.126 ± 0.236b |
| Syringic acid | 3.795 ± 0.248b | 3.330 ± 0.255b | 6.754 ± 0.990a | 1.651 ± 0.070c |
| Caffeic acid | 3.406 ± 0.700a | 0.667 ± 0.188c | 0.392 ± 0.008c | 1.537 ± 0.479b |
| Rutin trihydrate | 3.199 ± 0.578a | 0.635 ± 0.087b | 0.369 ± 0.054b | 0.405 ± 0.056b |
| p-Coumaric acid | 0.272 ± 0.009a | 0.155 ± 0.030c | 0.177 ± 0.035b | 0.152 ± 0.027c |
| Trans-ferulic acid | 6.150 ± 1.601a | 1.443 ± 0.067c | 1.418 ± 0.735c | 5.131 ± 0.851b |
| Apigenin 7 glucoside | 4.160 ± 0.493c | 12.854 ± 0.773a | 1.625 ± 0.790d | 8.230 ± 0.772b |
| Resveratrol | 0.128 ± 0.022c | 1.794 ± 0.112a | 0.524 ± 0.008c | 1.216 ± 0.098b |
| Quercetin | 3.816 ± 0.214b | 7.275 ± 0.048a | 2.681 ± 0.406c | 3.304 ± 3.610b |
| Trans-cinnamic acid | 0.296 ± 0.020b | 0.056 ± 0.007c | 0.410 ± 0.052a | 0.093 ± 0.112c |
| Naringenin | 3.398 ± 0.533a | 0.167 ± 0.056c | 1.954 ± 0.013b | 0.188 ± 0.010c |
| Kaempferol | 10.780 ± 0.279a | 5.642 ± 0.042c | 6.948 ± 0.452b | 5.601 ± 0.437c |
| Isorhamnetin | 7.592 ± 3.078b | 6.779 ± 0.230c | 9.258 ± 0.268a | 6.662 ± 0.250d |
| Eureka lemon | ||||
| Gallic acid | 6.306 ± 0.516b | 6.009 ± 0.196b | 11.221 ± 0.290a | 4.938 ± 0.201c |
| 3.4-Dihydroxybenzoic acid | 9.048 ± 1.019d | 12.666 ± 0.514a | 10.589 ± 0.661c | 11.649 ± 1.738b |
| (+)-Catechin | 4.459 ± 0.249c | 8.312 ± 0.328b | 12.577 ± 0.666a | 4.816 ± 0.394c |
| 1.2-Dihydroxybenzene | 4.821 ± 0.236b | 0.566 ± 0.025d | 3.687 ± 1.091c | 5.589 ± 0.448a |
| Syringic acid | 5.958 ± 0.858a | 1.242 ± 0.382c | 0.258 ± 0.079d | 1.810 ± 0.289b |
| Caffeic acid | 3.983 ± 0.294c | 4.763 ± 0.633b | 1.134 ± 0.143d | 5.323 ± 0.714a |
| Rutin trihydrate | 6.456 ± 0.591a | 2.377 ± 0.286b | 2.179 ± 0.559b | 0.195 ± 0.002c |
| p-Coumaric acid | 0.442 ± 0.215c | 0.524 ± 0.164b | 0.381 ± 0.194d | 1.202 ± 0.081a |
| Trans-ferulic acid | 2.673 ± 0.032a | 1.331 ± 0.154b | 0.682 ± 0.342c | 1.430 ± 0.343b |
| Apigenin 7 glucoside | 4.021 ± 1.158a | 1.466 ± 0.401c | 2.391 ± 0.624b | 1.930 ± 1.404c |
| Resveratrol | 0.422 ± 0.040a | 0.359 ± 0.058b | 0.187 ± 0.068d | 0.277 ± 0.005c |
| Quercetin | 4.865 ± 0.574b | 1.470 ± 0.162d | 5.199 ± 2.430a | 3.309 ± 0.356c |
| Trans-cinnamic acid | 0.066 ± 0.005c | 0.030 ± 0.006c | 0.157 ± 0.018b | 0.234 ± 0.017a |
| Naringenin | 0.378 ± 0.012b | 0.115 ± 0.001c | 0.547 ± 0.146a | 0.452 ± 0.063a |
| Kaempferol | 1.199 ± 0.238a | 1.237 ± 0.414a | 0.677 ± 0.211b | 0.614 ± 0.071b |
| Isorhamnetin | 0.901 ± 0.073c | 0.714 ± 0.026d | 1.102 ± 0.346b | 1.632 ± 0.372a |
| Orlendo orange | ||||
| Gallic acid | 4.830 ± 0.200b | 6.194 ± 0.118a | 6.356 ± 0.880a | 2.904 ± 0.867c |
| 3.4-Dihydroxybenzoic acid | 0.463 ± 0.037c | 3.224 ± 0.111b | 6.504 ± 0.529a | 3.439 ± 0.206b |
| (+)-Catechin | 8.906 ± 1.261c | 16.982 ± 0.541a | 5.268 ± 0.232d | 12.515 ± 0.411b |
| 1.2-Dihydroxybenzene | 2.745 ± 0.756d | 4.102 ± 1.180c | 24.984 ± 0.389a | 7.449 ± 0.752b |
| Syringic acid | 0.848 ± 0.040b | 0.848 ± 0.028b | 2.855 ± 0.048a | 0.634 ± 0.006c |
| Caffeic acid | 1.625 ± 0.151b | 2.839 ± 0.084a | 2.411 ± 0.046a | 0.983 ± 0.020c |
| Rutin trihydrate | 1.160 ± 0.025b | 1.139 ± 0.136d | 1.208 ± 0.041a | 1.146 ± 0.038c |
| p-Coumaric acid | 0.077 ± 0.025d | 0.173 ± 0.020c | 0.314 ± 0.015a | 0.223 ± 0.009b |
| Trans-ferulic acid | 0.261 ± 0.026d | 0.657 ± 0.023c | 1.255 ± 0.138a | 0.915 ± 0.156b |
| Apigenin 7 glucoside | 21.936 ± 0.850a | 2.488 ± 0.281c | 8.151 ± 0.092b | 1.138 ± 0.008d |
| Resveratrol | 0.145 ± 0.001b | 0.358 ± 0.060a | 0.345 ± 0.001a | 0.382 ± 0.021a |
| Quercetin | 0.531 ± 0.010d | 1.553 ± 0.190c | 10.375 ± 0.191a | 9.706 ± 0.635b |
| Trans-cinnamic acid | 0.115 ± 0.024c | 0.092 ± 0.013d | 0.622 ± 0.068a | 0.181 ± 0.007b |
| Naringenin | 0.256 ± 0.015c | 0.245 ± 0.031c | 0.708 ± 0.100a | 0.591 ± 0.081b |
| Kaempferol | 0.620 ± 0.028a | 0.575 ± 0.011b | –*** | – |
| Isorhamnetin | 0.932 ± 0.132c | 0.489 ± 0.034d | 1.210 ± 0.027b | 1.794 ± 0.005a |
* Mean ± SD; ** values within each column followed by different letters are significantly different (p < 0.05); *** nonidentified